Moved the action cluster out of the From row to a sibling of meta
inside .email-reader-meta. Undocked: cluster is absolute-positioned
top-right of the header so it overlays the From line as before.
Docked: cluster is in-flow at the bottom of the meta column, so it
sits below the From row when collapsed and below the To/Cc rows
when the user expands the recipient details via the chevron.
f569b9394e